From 07020ceeae31caa59cfd61ee4da4603872e1e660 Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Sun, 23 Jul 2023 21:35:02 -0600
Subject: [PATCH] lightpreview: add "Show Tris (See Through)" option

---
 lightpreview/glview.cpp     | 56 ++++++++++++++++++++++---------------
 lightpreview/glview.h       |  2 ++
 lightpreview/mainwindow.cpp |  4 +++
 3 files changed, 39 insertions(+), 23 deletions(-)

diff --git a/lightpreview/glview.cpp b/lightpreview/glview.cpp
index e36dc75c..76088198 100644
--- a/lightpreview/glview.cpp
+++ b/lightpreview/glview.cpp
@@ -427,29 +427,6 @@ void GLView::paintGL()
 
     QMatrix4x4 MVP = projectionMatrix * viewMatrix * modelMatrix;
 
-    // wireframe
-    if (m_showTris) {
-        m_program_wireframe->bind();
-        m_program_wireframe->setUniformValue(m_program_wireframe_mvp_location, MVP);
-
-        glEnable(GL_POLYGON_OFFSET_FILL);
-        glEnable(GL_POLYGON_OFFSET_LINE);
-        glPolygonOffset(-0.8, 1.0);
-
-        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-        QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
-
-        for (auto &draw : m_drawcalls) {
-            glDrawElements(GL_TRIANGLES, draw.index_count, GL_UNSIGNED_INT,
-                reinterpret_cast<void *>(draw.first_index * sizeof(uint32_t)));
-        }
-        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
-        glDisable(GL_POLYGON_OFFSET_FILL);
-        glDisable(GL_POLYGON_OFFSET_LINE);
-
-        m_program_wireframe->release();
-    }
-
     QOpenGLShaderProgram *active_program = nullptr;
 
     m_program->bind();
@@ -539,6 +516,33 @@ void GLView::paintGL()
 
     m_program->release();
 
+    // wireframe
+    if (m_showTris || m_showTrisSeeThrough) {
+        m_program_wireframe->bind();
+        m_program_wireframe->setUniformValue(m_program_wireframe_mvp_location, MVP);
+
+        if (m_showTrisSeeThrough)
+            glDisable(GL_DEPTH_TEST);
+        glEnable(GL_POLYGON_OFFSET_FILL);
+        glEnable(GL_POLYGON_OFFSET_LINE);
+        glPolygonOffset(-0.8, 1.0);
+
+        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+        QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
+
+        for (auto &draw : m_drawcalls) {
+            glDrawElements(GL_TRIANGLES, draw.index_count, GL_UNSIGNED_INT,
+                reinterpret_cast<void *>(draw.first_index * sizeof(uint32_t)));
+        }
+        if (m_showTrisSeeThrough)
+            glEnable(GL_DEPTH_TEST);
+        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+        glDisable(GL_POLYGON_OFFSET_FILL);
+        glDisable(GL_POLYGON_OFFSET_LINE);
+
+        m_program_wireframe->release();
+    }
+
     if (m_drawLeak && num_leak_points) {
         m_program_simple->bind();
         m_program_simple->setUniformValue(m_program_simple_mvp_location, MVP);
@@ -619,6 +623,12 @@ void GLView::setShowTris(bool showtris)
     update();
 }
 
+void GLView::setShowTrisSeeThrough(bool showtris)
+{
+    m_showTrisSeeThrough = showtris;
+    update();
+}
+
 void GLView::setDrawFlat(bool drawflat)
 {
     m_drawFlat = drawflat;
diff --git a/lightpreview/glview.h b/lightpreview/glview.h
index f61ca99a..e7088a76 100644
--- a/lightpreview/glview.h
+++ b/lightpreview/glview.h
@@ -80,6 +80,7 @@ private:
     bool m_fullbright = false;
     bool m_drawNormals = false;
     bool m_showTris = false;
+    bool m_showTrisSeeThrough = false;
     bool m_drawFlat = false;
     bool m_keepOrigin = false;
     bool m_drawPortals = false;
@@ -170,6 +171,7 @@ public:
     void setFullbright(bool fullbright);
     void setDrawNormals(bool drawnormals);
     void setShowTris(bool showtris);
+    void setShowTrisSeeThrough(bool showtris);
     void setDrawFlat(bool drawflat);
     void setKeepOrigin(bool keeporigin);
     void setDrawPortals(bool drawportals);
diff --git a/lightpreview/mainwindow.cpp b/lightpreview/mainwindow.cpp
index 040eb803..d5422e3f 100644
--- a/lightpreview/mainwindow.cpp
+++ b/lightpreview/mainwindow.cpp
@@ -172,6 +172,7 @@ void MainWindow::createPropertiesSidebar()
     auto *drawleak = new QCheckBox(tr("Draw Leak (PTS/LIN)"));
 
     auto *showtris = new QCheckBox(tr("Show Tris"));
+    auto *showtris_seethrough = new QCheckBox(tr("Show Tris (See Through)"));
 
     auto *keepposition = new QCheckBox(tr("Keep Camera Pos"));
 
@@ -191,6 +192,7 @@ void MainWindow::createPropertiesSidebar()
     formLayout->addRow(drawportals);
     formLayout->addRow(drawleak);
     formLayout->addRow(showtris);
+    formLayout->addRow(showtris_seethrough);
     formLayout->addRow(keepposition);
     formLayout->addRow(nearest);
     formLayout->addRow(bspx_decoupled_lm);
@@ -236,6 +238,8 @@ void MainWindow::createPropertiesSidebar()
     connect(fullbright, &QAbstractButton::toggled, this, [=](bool checked) { glView->setFullbright(checked); });
     connect(normals, &QAbstractButton::toggled, this, [=](bool checked) { glView->setDrawNormals(checked); });
     connect(showtris, &QAbstractButton::toggled, this, [=](bool checked) { glView->setShowTris(checked); });
+    connect(showtris_seethrough, &QAbstractButton::toggled, this,
+        [=](bool checked) { glView->setShowTrisSeeThrough(checked); });
     connect(drawflat, &QAbstractButton::toggled, this, [=](bool checked) { glView->setDrawFlat(checked); });
     connect(drawportals, &QAbstractButton::toggled, this, [=](bool checked) { glView->setDrawPortals(checked); });
     connect(drawleak, &QAbstractButton::toggled, this, [=](bool checked) { glView->setDrawLeak(checked); });